I'm thinking of starting an expriement but I believe I will need some help if there is anyone willing to offer it.

I used to work at a polypropylene manufacturing facility, where we used our loop reactors to make all different kinds of product; added stabilizers and extruded them thru huge machines into pellets, from super hard military applications and vehicles to welsh grape juice bottles and yoplait yogurt cups. That being said I know a lot about them and the different stabilizers we used to attain certain hardnesses or clarity etc. I still have access to this information, and I also have the ability to acquire the poly "pellets", as it is loaded onto 283k lb railcars, and a 50lb bag of the stuff is nothing to get. I'm thinking of getting some different types, and attempting to make cylinder blanks from them. If my memory serves, I'll need to heat the poly up to 250C to get it to melt (depending on type it can be lower) and it cools very rapidly without any air bubbles and can be rather smooth without any help. However I need to figure out a mold, and also any ideas on the best way to do this or past practices. I figure with the ability to customize the hardness among other things, I think we can get a cheap replacement for wax cylinders. Or at least attempt it and see where it goes.

I'm interested in your thoughts before I spend the time to tackle such a feat. What kinds of properties would be best in a cylinder for recording and long term playability etc. I would also like the ability to shave with ease, which I think can be done.

I've done some reading, and polypropylene is certainly quite versatile. I wonder, though, how well would plastic like that record? You mentioned that the softness can be altered, but to what degree so that a decent recording can be made? And one more thing. Would you construct this from pure polypropylene, or have a core of some kind? This seems like a great idea with the information you've given us, and that I've read.

I've done some reading, and polypropylene is certainly quite versatile. I wonder, though, how well would plastic like that record? You mentioned that the softness can be altered, but to what degree so that a decent recording can be made? And one more thing. Would you construct this from pure polypropylene, or have a core of some kind? This seems like a great idea with the information you've given us, and that I've read.

Good Luck!

That's the big question...how well will it record. I know some on YouTube have dabbled and been successful. I would think I would be able to construct it from pure poly, but I would like to expriement. Some of the plastics can be made extremely light, so that will be interesting as well. The softness can be altered quite a bit, to something so runny it's like water when melted to where it's so hard it'll break shear pins the size of my arm on HUGE gear pumps that push it thru the extruder...which is a big difference. For an idea what we used this stuff for I included some examples off the website. I need to figure out a mold though.

I found these mold designs online. I'm wondering if this will work for what I'm thinking of doing if anyone has experience. I was thinking of giving this to some machinists and see if they can create it for me.

I had pondered this idea once, some years ago, after reading of Henri Lioret's method of recording on celluloid.

As I don't have the technical or chemical experience for this sort of thing, I never tried to realize it; but the question remained of what sort of polymer to use. The melting point would have to be rather low, in order to soften the blank in, say hot water, as Lioret did; but the surface when cooled would have to be hard enough to withstand prolonged, repeated playing. The consistency of the material would also have to be fine and homogenous enough to allow for a clean cut and minimal surface noise. You don't want it to be too grainy or splintery to be listenable, or too rubbery to make a good cut.

More research into available polymers would be helpful: this is a project that will take much time and labor to carry out successfully. Remember, it took Edison's laboratory, and the Graphophone company, years of work to get just the right wax formula.

So did you ask Chuck Richards permission to post his mold design? He is a member here, and his page is copyrighted. He does encourage experimentation though, and that is why he made the page. It is a smooth bore mold, still a great design, I have seen it work in person. I use spirals in my molds, to be a little different, however it also allows more working time, and grace when molding blanks, smooth bore molds have a smaller window of extraction time, the compound will bind while spirals decrease some pressure as the compound shrinks allowing more grace period for extraction. You will want to make your recording a few percent bigger, and the center so it can be reamed out on a reamer, to center your recording. metallic soap had the advantage you could have it cool on metal cores to keep it from distorting, of course you are talking of molding a blank of the plastic and recording on it. I would rather make a metallic soap blank and make a silicone or Nickel copper mold from the master. I know I know, you guys just want to thumb your nose at us Metallic soap enthusiasts.

So did you ask Chuck Richards permission to post his mold design? He is a member here, and his page is copyrighted.

You don't need permission to re-post something that's publically available on the internet as long as you cite the source. Since we can see the URL in his screen shots I'd say that's sufficient citation.

So did you ask Chuck Richards permission to post his mold design? He is a member here, and his page is copyrighted.

You don't need permission to re-post something that's publically available on the internet as long as you cite the source. Since we can see the URL in his screen shots I'd say that's sufficient citation.

That's generally true for a short excerpt, which would be covered under "fair use". Reposting several pages of material without permission is not "fair use", even if properly cited.

At 250*C, you're venturing beyond the ratings of silicones. You may need to have a metal mold made via electroplating. I have quite a bit of experience with polyurethane, silicone and PTFE. If I can be of any assistance, please PM me.

Poly plastics are great. Metallic soaps are great. Shellac is great. It all comes down to cost and whaf materials we know how to work with.

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